The Clinical Core has been in operation for twenty years to provide services that foster the translational interface between basic science, clinical, behavioral, and epidemiologic investigators and HIV-infected patients. The Specific Aims of the Clinical Core are: 1. To provide a Comprehensive Specimen Repository offering the efficient collection, processing, storage, quality assurance tracking, distribution, and shipping of clinical specimens obtained from wellcharacterized patients for collaborative investigations involving multiple research disciplines. 2. To provide an innovative Computerized Database and Informatics Servicethe resources and equipment to store and access complex, interactive data and the expertise to assist with study design, identify subjects who meet entry criteria for research protocols, conduct appropriate data analyses and provide detailed and relevant interpretation of results. 3. To establish new methods and technologies to make clinical samples more readily accessible to CFAR members realizing that despite the numerous successes we have had in fostering innovative translational research, we must strive to improve this process. 4. To provide Research Training Services to support all levels (from students to research staff to seasoned faculty updating their skills) of domestic and international clinical research. While each of these services has been in operation since the beginning of our CFAR, each continues to grow and diversify substantially in response to investigator needs. Publications requiring Clinical Core services have continued to increase every year during the last funding period. Specimens are integrally linked with information in the Computerized Database, and this synergy has played an important role in new discoveries related to HIV pathogenesis, understanding immune responses and vaccine development. Recently, the medical record system and research database have become fully electronic, utilizing software completely designed and managed by CFAR investigators with expertise in informatics, statistics and computer technology. These advancements place CFAR investigators in a unique position to lead collaborative clinical database and outcomes-based national and international projects, and to contribute meaningfully to policy debates regarding health care access and cost-effectiveness. A variety of domestic research training services have been strengthened, while international research training efforts are best exemplified by Clinical Core support, in full collaboration with the International Core. These Clinical Core services are essential for the conduct of a vast array of HIV/AIDS research at DAB and around the world.